He teleported directly in front of Mjolnir's path, I don't see how it could be anything BUT teleporting across the battle field.

I'm not gonna lie, it looks like he's teleporting under his own power without Mjolnir in the trailer.

I don't really dare hope that he's teleporting on his own yet since the visual effect looks very much like the Bifrost. It of course doesn't seem like a normal arrival on the Rainbow Bridge either, seeing how Mjolnir is already there.